Blocking protein fraction recovery method and product

Abstract

A process is provided for the isolation of a protein fraction herein termed the "blocking protein fraction" or "BPF", from mammalian blood. The process comprises a series of centrifugal separations of blood fractions under conditions which maintain the integrity of the desired material as it existed in vivo. The blocking protein fraction, is a new material and it constitutes another aspect of the disclosure. Isolated BPF, a natural protein or a derivative thereof, is useful to prevent tissue implant rejection, and as standard from the determination of the tumor remission activity of other materials isolated from blood.

What is claimed is: 
     
       1. A process for the isolation of BPF which comprises: (a) suspending whole blood in a buffer solution of nearly neutral pH   (b) centrifuging the whole blood suspension at 5400-10,000g to obtain a first supernatant   (c) centrifuging the first supernatant at 20,000 to 25,000g to give a BPF sediment   (d) optionally purifying the BPF sediment by resuspending it in an alkaline buffer and centrifuging at 20,000-25,000g to give a supernatant containing relatively pure BPF.   
     
     
       2. The process of claim 1 wherein the centrifuging of step (b) is conducted at 6500g. 
     
     
       3. The process of claim 1 wherein the centrifuging of step (c) is conducted at 23,500g. 
     
     
       4. The process of claim 1 wherein the centrifuging of step (d) is conducted at 23,500g. 
     
     
       5. A process for the isolation of BPF comprising (a) suspending whole blood in a nearly neutral buffer solution   (b) centrifuging the whole blood suspension at 6500g to obtain a first supernatant   (c) centrifuging the first supernatant at 23,500g to give a BPF sediment   (d) optionally resuspending said BPF sediment in an alkaline buffer and centrifuging at 23,500g to give a supernatant containing relatively pure BPF.   
     
     
       6. The isolated product by the process of claim 1. 
     
     
       7. The isolated product by the process of claim 5.